Submitted by: Ted Peters


The field of astroethics, or the ethics of space exploration, requires both an adumbration of existing and future moral quandaries plus a philosophical foundation persuasive to both the scientific community and the globe's plurality of religious traditions. The latter is not taken up here. Yet, in this entry fifteen existing and projected moral quandaries are listed and discussed. Quandaries such as whether Planetary Protection  implies that life on Mars, Enceladus, or other off-Earth locations should be treated with intrinsic value or merely instrumental value?  Will Earth's space explorers have the right to bull doze over biospheres? Or must we assume the responsibility of protecting alien life forms? When it comes to communication and engagement with intelligent life most likely residing on exoplanets elsewhere in the Milky Way, would our moral responsibilities differ depending on whether ETI is intellectually inferior, our peer, or our superior? Would our moral responsibilities would also differ depending on whether ETI is hostile, peaceful, or salvific? This treatment of astroethics is framed within a structure of Quandary-Responsibility Ethics that treats the Milky Way as a Galactic Commons.


The United States, Russia, China, India, and Europe are all going to space. Separately. Here is the mission statement of the Indian National Committee for Space Research (INCOSPAR): "Harness space technology for national development, while pursuing space science research and planetary exploration."[1] Plans for the future include launching a number of new-generation Earth Observation Satellites, sending unmanned missions to Mars and Near-Earth Objects (NEOs), developing a reusable launch vehicle, interplanetary probes, and sending a spacecraft mission to the sun. Soon representatives of the people of India will engage in off-Earth interaction. So will astronauts from countless other nations and even private enterprises.[2] 

Once we look back at Earth from space either through an astronaut's naked eyes or electronic scopes, we see but one single glowing blue planet. We do not see borders between countries nor divisions between races, religions, or soccer teams. When we gaze out toward space and then back again at our terrestrial home, we get a sense of unity, oneness, holism. Does this perception of terrestrial and even extraterrestrial oneness suggest how we might go about assessing ethical quandaries? 

This entry deals with astroethics--that is, ethical reflection on quandaries arising from space exploration.[3] The time is ripe. The UNESCO Ethics of Science and Technology Programme was created in 1998 with the establishment of the World Commission on the Ethics of Scientific Knowledge and Technology (COMEST) "to give an ethical reflection on science and technology and its applications."[4] 

The ethics of space exploration, according to James Schwartz, "must develop slowly and alongside our pursuits in space.it should function as a reflective guide for these pursuits."[5] In pursuit of this reflective guide, we here will list fifteen moral quandaries arising from current plans for space exploration, demonstrating the need of the present generation to ascertain its responsibility toward off-Earth entities and activities. We will frame these issues in terms of Quandary-Responsibility Ethics. "The ethics of responsibility is the ethics of care and concern. It demands that scientists and technologists investigate all possible consequences of their professional work on different segments of society," contends A.N. Tripathi, professor at the Institute of Technology at Banaras Hindu University.[6] The Quandary-Responsibility framework will allow us to formulate issues and assess their urgency without requiring the philosophical or theological homework of justifying a moral foundation.  The net product will be a quandary-responsibility approach to astroethics leading to public policy formulation. 

Within the Solar Ghetto: Twelve Astroethical Quandaries  

The ethical chef, mixing quandary with a sense of responsibility, will quickly see the need to cut the ethical pie into two large slices. The first slice designates our solar ghetto as the ethical commons, whereas the second slice will allow us to reach out to the larger Milky Way metropolis. 

Astrobiologists regularly distinguish between the search for extraterrestrial non-intelligent life (ETNL) within the solar system and the search for extraterrestrial intelligent life (ETIL or just ETI) on exoplanets elsewhere in the Milky Way.[7] Enceladus, Titan, Europa, Ganymede, and Callisto, moons orbiting Saturn and Jupiter, are good candidates for ETNL.[8] SETI (Search for Extraterrestrial Intelligence Institute), in contrast, aims its radio telescopes at extra-solar stars in the Milky Way and even more distant galaxies. SETI listens for signals. The exobiological search for ETNL is intrusive; it employs spacecraft, landings and visits to other possible ecospheres by probes or even astronauts. The SETI search is non-intrusive; it simply listens for signals that might indicate the past or present existence of ETIL. METI (Messaging Extraterrestrial Intelligence) International, however, is electronically intrusive.[9] METI broadcasts terrestrial messages to targeted extraterrestrial sites. These different search methods have elicited two domains for ethical reflection, one for our solar ghetto and another for the larger Milky Way metropolis. 

We may thank SETI astrobiologist Margaret Race and Methodist theologian Richard Randolph for proposing four principles for developing an ethical scheme appropriate to the discovery of non-intelligent life within our solar ghetto: (1) cause no harm to Earth, its life, or its diverse ecosystems; (2) respect the extraterrestrial ecosystem and do not substantively or irreparably alter it (or its evolutionary trajectory); (3) follow proper scientific procedures with honesty and integrity during all phases of exploration; and (4) ensure international participation by all interested parties.[10] In this spirit we will turn to a number of issues arising from the prospect that our space explorers will find microbial life close to home and intelligent life elsewhere in the Milky Way metropolis. 

We begin close to home, to our solar system and the search for microbial life within it. We can quickly adumbrate an initial formulation of a dozen moral quandaries:[11]  (1) does planetary protection from alien contamination apply to Earth alone, or are we earthlings responsible for protecting off-Earth biospheres? (2) does extraterrestrial microbial life have intrinsic value warranting our protection?[12] (3) should space explorers invoke the Precautionary Principle when planning intrusions into off-Earth biospheres? (4) how should we manage moral responsibility for cleaning up the 22,000 tons of space junk earthlings have already left in Earth's orbit? (5) should satellite surveillance be permitted and controlled?  (6) should nations weaponize space? (7) which gets priority to off-Earth sites: scientific research or making a profit?  (8) should we earthlings terraform Mars? (9) should we earthlings colonize Mars? (10) how should we protect Earth from extraterrestrial threats such as asteroids? (11) does astroethics require a single planetary community of moral deliberation? (12) should the Common Good include the solar system and even the Galactic Commons? It might be too early to resolve each of these issues, but simply formulating them as quandaries for moral deliberation could provide a service for public policy makers.  

Planetary Protection?

Does Planetary Protection from alien contamination apply to Earth alone, or are we earthlings responsible for protecting off-Earth biospheres?  Does space exploration endanger Earth? Does space exploration endanger off-Earth biospheres? Planetary protection or PP is how we tag these quandaries. 

PP--"Planetary Protection is the practice of protecting solar system bodies from contamination by Earth life and protection of Earth from possible life forms that may be returned from other solar system bodies"--is the single most urgent item on NASA's list of ethical concerns. PP policy is aimed at protecting terrestrial ecosystems from contamination by alien life forms that may be destructive. The risk of contamination goes in two directions, forward and backward. The possibility of forward contamination alerts us to the risk of disturbing an already existing ecosphere; the introduction of Earth’s microbes carried by our spacecraft or equipment could be deleterious to an existing habitable environment. Back contamination would occur if a returning spacecraft brings rocks or soil samples that contain life forms not easily integrated into our terrestrial habitat. A quarantine program will be required to determine the safety of newly introduced ETNL. 

The United Nations also deems this important. Article IX of the 1967 Outer Space Treaty (OST) states that “.parties to the Treaty shall pursue studies of outer space including the Moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, shall adopt appropriate measures for this purpose.” Today, COSPAR (UN Committee on Space Research) hosts the PPP ( Panel on Planetary Protection ). The PP principle has been guiding earthlings since 1967. 

In practice, prevention of backward contamination trumps protection against forward contamination. Preventing harmful contamination of the Earth must be of the "highest priority" for all missions, argue John Rummel and Catherine Conley.[13] 

Nevertheless, astroethicists may apply the term, planetary protection, both to Earth and other off-Earth bodies as well. With tacit obeisance to the cosmic commons, planetary protectionists ought to assume we on Earth are responsible for protecting ecosystems on other planets from the destructive influence of human visitation. It is easy to see why we might wish to protect Earth. It's a matter of survival. Survival has a way of trumping all other moral priorities. We cannot act responsibly if we are dead. At least, this is the way many among us think. So, giving priority to protecting Earth from an invasion by a dangerous microbe seems to be a most reasonable stand to take. Yet, we must ask: are we also morally responsible for what happens on other planets? This leads us to the next on our list of issues, the question regarding the intrinsic value of life. 

Applying the same standard of PP to off-Earth celestial bodies is controversial. Some scientists will complain that rules and regulations will constrict wildcat exploration. "Mars will be just fine on its own.and the stringent safeguards now in place discourage scientists from exploring the Red Planet,"[14] writes Nathan Collins. Yet, Mars has its planetary protectors. Catherine Conley, NASA's former planetary protection officer rises to Mars' defense: "If you want to study life elsewhere, you have to make sure not to bring Earth materials along."[15] If Martian microbes could speak English, they might say: "thank you NASA."  

Intrinsic Value?

Does extraterrestrial microbial life have intrinsic value warranting our protection? 

 In the event that terrestrial space explorers discover microbial life on Mars or Enceladus, what will be our moral responsibility? Does off-Earth life have intrinsic value or merely instrumental    value? Do earthlings have the right to exact genocide on off-Earth life forms? If not, how much respect do we owe our space neighbors? Why?[16]

 Intrinsic value--"value that is truly independent of valuing agents--seems difficult to justify," avers Mark Lupisella at Goddard Space Flight Center.[17] He's right. The concept of intrinsic value is difficult to justify philosophically. Nevertheless, Lupisella proceeds to justify treating extraterrestrial life as if it has inherent or intrinsic value on the grounds that it is not other. He rejects alterity. We earthlings are connected to all life, on Earth or beyond. We are connected by our shared evolutionary history. The "fundamental property" of the universe is "connectedness," he argues; and this connected relationship obligates earthlings to treat non-earthlings with due respect. "Intrinsic value.is realized through ever-increasing degrees of relationship."[18] In short, microbes living on Mars or Enceladus should expect earthlings to treat them as if they have intrinsic value. 

Phenomenologically, Lupisella's argument could be strengthened by observing that all valuing--including intrinsic value--requires a relationship between what is valued and a valuer. Indirectly, Charles Cockell supports Lupisella. "Whether intrinsic value is something inherent in an object or something projected on to it, we definitely do need a valuer for that value to become of any ethical relevance."[19] The role of relationship here is much easier for the theologian than the philosopher, because the theologian can appeal to God as the primal valuer. 

Richard Randolph, cited above, follows this path. He affirms the intrinsic value of life by appeal to God.  "From a Christian point of view, God's preferential option for life means that all of life has intrinsic value. By this I mean that all living organisms, as well as their ecosystems, are entitled to a basic, underlying level of respect--and, even reverence--by humans. Every living organism is good in and of itself, regardless of the instrumental value it may have for humans."[20] We human beings on Earth should express this intrinsic worth of extraterrestrial life by behaving as servant/stewards, supporting both living organisms and their respective habitats wherever they may be found. "God's preferential option for life grounds the claim that all of life has intrinsic worth and that God intended for extraterrestrial life to flourish and be self-determinant."[21] 

Responsibility for life's intrinsic value does not require a total hands-off policy, to be sure. It does not require a total ban on killing individual creatures.[22] Each day here on Earth we kill microbes by the millions when sanitizing our hands with an anti-biotic. Whenever we eat, we nourish ourselves from the death of other living things, plants in salads and animals in meat. We can respect the fact of life--the brute presence of life--while still discriminating between individuals and preserving the very existence of life per se. 

Durham University Bioethicist Celia Deane-Drummond contends that the concept of intrinsic value does not preclude discriminating between greater or lesser worth.  "It is possible to hold to the notion of intrinsic value, while also being able to discriminate between different forms of life and non-life in terms of their worth."[23] 

What comes next? At the 2010 COSPAR conference held at Princeton, it was suggested by scientists in attendance that we turn off-Earth biospheres into parks. Parks would provide protection and management of life.[24] Might this be a good idea?  

Precautionary Principle?

Should space explorers invoke the Precautionary Principle when planning intrusions into off-Earth biospheres?Might astroethicists borrow the Precautionary Principle from terrestrial ecologists?  The Wingspread Definition of the Precautionary Principle, formulated at the 1992 United Nations Conference on Environment and Development, looks particularly apt. “When an activity raises threats of harm to human health or the environment, precautionay measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of the process or product, rather than the public, should bear the burden of proof."[25]

 When space scientists and ethicists met at Princeton for a COSPAR workshop in 2010, they embraced a variant formulation: "we define the precautionary principle as an axiom which calls for further investigation in cases of uncertainty before interference that is likely to be harmful to Earth and other extraterrestrial bodies, including life, ecosystems, and biotic and abiotic environments."[26]

 Employment of the precautionary principle for space exploration provides the kind of middle axiom that connects the larger value of life with practical policies that facilitate off Earth activities.  

Space Junk?

How should we manage moral responsibility for cleaning up the 22,000 tons of space junk earthlings have already left in Earth's orbit?

 Currently, more than 500,000 pieces of debris, or “space junk,” are tracked as they orbit the Earth. They all travel at speeds up to 17,500 miles per hour, fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft.[27] We earthlings have turned our upper atmosphere into a trash dump. Do we want to pollute extraterrestrial space just as we have befouled our terrestrial nest? 

 The problem with our orbiting landfill is not merely that it is ugly. It is also dangerous. It risks danger to future space flights and future satellites. Paul Marks warns us: “there are now 22,000 human-made objects larger than 10 centimeters across in orbit and half a million larger than 1 centimetre—and all pose a grave risk to space missions.Even if space agencies never launched another rocket, the cloud of debris will continue to grow as a pieces of space junk crash into one another.”[28] As space junk crashes, each piece fragments and multiplies the number of dangerous micrometeorite material that risks damage to future space vehicles we send up. Some space scientists fear a runaway chain reaction--called the Kessler syndrome--that pulverizes everything in orbit, including functioning satellites. This would establish a band of untraversable danger, a no-man's land in space. Here is the warning: for safety's sake, stay out of the space dump.

 To date, no one has been held responsible for space junk. Those who make profits or who otherwise gain from sending this material into space are not required to recycle or dispose of their waste. Space waste accumulates, but nobody is required to pay for cleaning it up. Nations or corporations treat the Greater Earth or cosmic commons as their ashtray, as a public trash dump. Follow the money.

  If we would define Greater Earth as a part of the galactic commons, then we would find ourselves already beset with a classic moral problem: those with power and influence utilize common space for their own profit while the population as a whole absorbs the cost of deterioration or degradation of what is publically shared. If and when our planetary society consolidates its diversity into a single community of moral deliberation, then responsibility will need to be parsed and parceled according to a renewed principle of justice.

  The European Space Agency has set up a Space Debris Office to coordinate research activities in all major debris disciplines, including measurements, modeling, protection, and mitigation, and coordinates such activities with the national research efforts of space agencies in Italy, the United Kingdom, France and Germany. Together with ESA, these national agencies form the European Network of Competences on Space Debris.[29]

  The Japan Aerospace Exploration Agency (JAXA) is testing to see if a tethering technique might begin the process of debris-gathering. The tether consists of a long conductive wire attached to a junk chunk which, by implementing an electrodynamic drag, would pull the debris into the atmosphere where it would burn up. The Space Thethered Autonomous Robotic Satellite-2 (STARS-2) is testing the idea and, if it works, then it could be attached to future missions aimed at capturing existing debris.[30]

  Jacques Arnould at the French Centre National d'Etudes Spatiales ICNES) admonishes us. "It is mankind's moral duty, plus the necessity to protect astronauts and satellites, and to ensure the continuation of space activities around the Earth that forces us to deal with the issue of space debris, even if, strictly speaking, there is currently no law pertaining to the non-proliferation of orbital debris."[31]  

Satellite Surveillance?

Should satellite surveillance be permitted and controlled?

Like Google and Facebook, space now wants your personal information. Should we say "good-bye" to privacy?

  For the last six decades reconnaissance satellites or spy satellites have been deployed for purposes of military or intelligence applications. The telescopes on board are pointed toward Earth, not toward the stars. Mission tasks include high resolution photography; measurement and signature intelligence; communications eavesdropping; covert communications; monitoring of nuclear test ban compliance; and detection of missile launches. With the improvements in technology, today's spy satellites have a resolution capacity down to objects as small as ten centimeters. Surveillance satellites also provide us with efficient communications, weather reporting, Google maps, and many more public services. 

 "Can a State gather information about the natural riches and resources of another sovereign State without having obtained the latter's prior agreement?" asks Arnould. "Is it not up to the remote sensing State to ask for the prior permission of the State whose territory is being observed?"[32] This sounds like a reasonable ethical question. Yet, it presupposes the present situation of sovereign nation states, a political system that may have made sense prior to the current thrust toward economic and technological globalization. Satellite surveillance and communication services, right along with other space activities, are playing into an emerging planetary consciousness. 

Protecting national boundaries from foreign intelligence or even public transparency may soon be an artifact of history, an era we remember but no longer live in. Perhaps the way forward is to support an ethic of maximal information without discrimination. Rather than attempt to police information gathered from remote sensing, it would be healthier and easier to prevent such information from deleterious usage. 

Weaponize space?

Should nations weaponize space? Two U.S. presidents, Ronald Reagan and Donald Trump, have thought so. Both have viewed space as a warzone, a battlefield in which the American military should hold hegemony. For Reagan, it was called "Star Wars." For Trump, "Space Force." The problem is that the United Nations forbids the militarization of space. 

In the case of President Trump, space is “a warfighting domain” and the United States needs to be ready for combat there. On August 8, 2018, U.S. Secretary of Defense James Mattis said that space is “is becoming a contested war-fighting domain…and we’ve got to be able to compete, to deter, and to win.” U.S. Vice President Mike Pence said the U.S. Space Force would be a “unified combatant command for space.”

 Let's return for a moment to the 1967 United Nations Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies, known as the 1967 Outer Space Treaty (OST). The OST states without equivocation that space is to be used "exclusively for peaceful purposes." The United States ratified this treaty in 1967. More than 100 nations are party to the OST. For 50 plus years, the treaty has served as an international legal framework for maintaining outer space as a commons to be used, and protected, for peaceful purposes. 

NASA communications consultant Linda Billings is outraged. 

Citizens of my country – to which I am devoted – can, and should, press their elected officials to abide by the central tenet of the Outer Space Treaty and preserve space for peaceful purposes. Instead of preparing for 'warfighting' in space, the United States could – and should – take a global leadership role in pursuing diplomatic and other avenues for preempting any possibility of warfighting in space. It’s the right thing to do.[33]

Science versus Making a Profit?

  Meet the Dream Chaser. Designed by the Sierra Nevada Corporation, the Dream Chaser is a reusable space utility vehicle for uncrewed or crewed missions. It launches vertically and provides a low-g re-entry for a gentile runway return. It's designed to transport cargo from Earth to destinations above. It's for rent.

It no longer takes a government to pay the space travel ticket. Private enterprise is now investing. We are on the brink of an era of space tourism, with the first trips to suborbit and  low orbit vacations in the planning stages. Visits to the moon will most likely follow. Establishing research laboratories on the moon and Mars are being envisioned. Might we be wise to ready ourselves for an El Dorado type of gold rush to the new extraterrestrial world? If so, should we try to put policies and policing mechanisms in place in advance?

   Up until this point we have thought of outer space as a sandbox for Earth's scientists to play in. Governments have found the money to fund modest exploratory adventures; and scientists have organized to conduct experiments which have yielded an abundant harvest of new knowledge about our cosmos. Frequently, scientific goals have been mixed with military goals, because leaders in the military have been willing to share their budgets for scientific purposes. 

 Scientific experiments do very little damage, if any. Somewhere on the Moon is a golf ball left by visiting astronauts. Landing probes on Mars or on Titan has not infected or contaminated anybody's ecosystem, as far as we know. The impact on our solar system by scientific activity is benign. 

With the private sector now ogling space for profit, this situation is about to change. What about space tourism? Simply flying a few wealthy passengers high enough to experience weightlessness is not likely to provoke anyone's moral ire. But, what about tour busses roaming the surface of the Moon? Busses will leave tire tracks. Perhaps trash. No doubt tourists will want to visit that golf ball as well as historical sites where astronauts first landed. Will the crowds of visitors damage those sites? Are those sites sacred? Protectable? Who will decide and what will be the criteria by which they decide?          

What is the future of commercial space travel? The market does not always react the way the marketers predict. Low cost and frequent flights to suborbit heights might actually encourage increased participation by scientists. These scientists will want to do research on the ignorosphere. The ignorosphere is a level just above balloon traffic but too low for satellites. Scientific researchers might buy tickets with the tourists and then look out the windows.[34]  

Terraform Mars?

 Should we earthlings terraform Mars? Or, any other planet or moon, for that matter? Will we Earthlings rest content until we see the golden arches of McDonalds on the red planet? 

Christopher McKay, a space scientist at NASA's Ames Research Center, has been dreaming about this for years. According to McKay, we work with the assumption that Mars is lifeless. At least it is lifeless today. The red planet may have been home to life in the past; but Mars must have lost its atmosphere and its ability to sustain life for reasons yet unknown. Its thin atmosphere is replete with carbon dioxide, but not oxygen. Let us speculate: suppose we would transplant living organisms from Earth that take in carbon dioxide and expel oxygen into the atmosphere? Then, when enough oxygen suffuses the atmosphere, we could introduce oxygen inhaling organisms that expel greenhouse gases. These greenhouse gases would warm up Mars, and life would thrive. A self-regenerating ecosystem could run on its own. In less than a century, estimates McKay, we could establish a biosphere that would last ten to a hundred million years. 

Planetary ecosynthesis is what McKay calls this terraforming project. His proposal for planetary ecosynthesis raises a number of ethical concerns. Immediately, one might ask: should we do it? How can we responsibly speak to this quandary? 

McKay starts with a simple axiom: life is better than non-life. Virtually no one who mulls over the question of life's intrinsic value would challenge this axiom. But, we ask: what are the corollaries? 

On Earth the principle that life is better than non-life has influenced our decisions and policies to preserve life. We preserve species from distinction. We preserve habitats to encourage certain species to proliferate. In short, we attempt to prevent certain forms of life from dying out. 

This would not apply to Mars, however. If we assume that Mars is currently lifeless, then we would not find ourselves considering the preservation of life. Rather, the question arising is this: should we seed life on Mars? If life is better than non-life, says McKay, then the moral answer should be in the affirmative. Transferring terrestrial life forms to Mars would be better than leaving Mars lifeless. 

Curiously, McKay appeals to both intrinsic value and instrumental or utilitiarian value when justifying planetary ecosynthesis. First, the intrinsic argument. Because life has intrinsic value, Mars with life would be ethically of greater worth than a lifeless Mars, even if it is transplanted life. Second, the instrumental argument. Because we on Earth would learn so much from the Mars project about sustaining a biosphere, we could apply what we learn on Mars to sustaining Earth's biosphere in the face of our imminent ecological challenges. "Both utilitarian and intrinsic worth arguments support the notion of planetary ecosynthesis."[35]

 How might such an argument sit with a theologian? With a Buddhist theologian? Frencisca Cho, Associate Professor of Buddhist Studies at Georgetwon University, offers a Buddhist interpretation. “A Buddhist would apply neither an intrinsic nor instrumental value of life or nature to the question of terraforming Mars. The idea of an intrinsic value would go against the principle of emptiness. Instrumental value, on the other hand, would be problematic because one could not ensure that the instrumental objectives and the proper motivations.There is no intrinsic worth to nature but neither is there intrinsic worth to human beings.There is no option between them, so you have to transcend that framework all together.”[36] From a Buddhist perspective, neither an appeal to the intrinsic value of life nor an appeal to life's utilitarian value to human beings provides ethical guidance for the terraforming question.

 Here is the quandary: should we terraform Mars or any other celestial body within our sola ghetto? On the one hand, McKay's argument that life is better than non-life provides a sound point of departure. On the other hand, transplanting terrestrial life to an extraterrestrial location looks a great deal like colonizing. As we bring the history of terrestrial colonization to mind, we cannot avoid recalling the imperialism and greed that motivated colonization and the devastating impact of exploitation and genocide on the lands colonized. What would be our moral responsibility on this matter? 

Colonize Mars?

Should we earthlings colonize Mars? Yes, says Mars Society director Robert Zubrin with enthusiasm: "Mars can and should be settled with Earth émigrés."[37] No, says Linda Billings emphatically. "Humans should clean up the mess they have made on their home planet and learn how to take care of one another before they go off into space."[38] Other astroethicists such as James Schwartz and Christopher McKay support Mars colonization only after certain preconditons are met.

"Humans-to-Mars" is the direction Robert Zubrin is leading his followers in the Mars Society. His "Mars Direct" colonization plan "advocates a minimalist, live-off-the-land approach to exploring the planet Mars, allowing for maximum results with minimum investment.  Using existing launch technology and making use of the Martian atmosphere to generate rocket fuel, extracting water from the Martian soil and eventually using the abundant mineral resources of the Red Planet for construction purposes, the plan drastically lowers the amount of material which must be launched from Earth to Mars, thus sidestepping the primary stumbling block to space exploration and rapidly accelerating the timetable for human exploration of the solar system."[39] Money raised from the private sector will support this effort. Mars Society adherents see themselves as rivals to NASA. They are in a space race and plan to beat NASA to the fourth planet.  

In the summer of 2013 the project planners began their selection of the first crew headed for the Red Planet in 2023. The crew would be given seven years of training in engineering, medicine, agriculture, and astrophysics. This would be a one way trip. Once the astronauts have landed, they would become Martians. 

The mood of the Mars Society and the Mars One project is one of promethean expectation. The human race is being called by destiny to go, go, go. To spread our race throughout the solar system fulfills our inherited evolutionary mandate, to fill every niche with life. 

  Linda Billings, cited above, objects. We earthlings have already spoiled one planet. Will we spoil others? Theologian Cynthia Crysdale recommends that we incorporate this risk into our ethical vision. "We need to think of ourselves as living within an ethic of risk, not an ethic of control. I say this in direct reference to the actions we take in terraforming or colonizing or exploring other planets. My caution is to point out that the conditions of possibility that we establish in the hopes of one outcome may at the same time establish conditions under which totally unforeseen schemes of recurrence become established."[40] Dr. Crysdale has wisely asked us to consider human nature--that is, human sinfulness--when making plans. No ethical justification could suffice without acknowledgement of who we are as humans. Nevertheless, anticipating the unforeseen damage we humans are capable of is a principle one must incorporate into any such project, regardless of whether it is justified by appeal to an intrinsic or utilitarian ground. 

Protect Earth from Heaven?

How should we protect Earth from extraterrestrial threats such as asteroids?

We are not safe simply remaining home on the third planet and minding our own business. Earth is a dangerous home. The heavens hold plenty of threats. The Sun occasionally launches solar flares, which fry electricity grids by generating intense currents in wires. A solar megastorm in 1859 sparked fires in telegraph offices. If such a flare would reach Earth today, it would knock out satellites and shut down power grids for months or longer. Such an event would incur trillions of dollars in economic damage. Although we rely upon the sun for our daily life, some day it just might kill us.

 The sun is not our only threat. We also need to anticipate the possibility of a large comet or asteroid strike. On February 15, 2013, more than 400 Russian people were injured when an asteroid exploded just above the city of Chelyabinsk. NASA referred to it as a “tiny asteroid” that measured roughly 45 feet across, weighed about 10,000 tons and traveled about 40,000 mph. The object vaporized roughly 15 miles above the surface of the Earth, causing a shock wave that triggered the global network of listening devices that was  established to detect nuclear test explosions. The force of the explosion measured between 300 and 500 kilotons, equivalent to a modern nuclear bomb. [41]

 Within hours of the Russian disaster, another asteroid, 2012 DA14 passed between Earth and our geosynchronous satellites. Once or twice every two million years our planet gets smacked by rocks two kilometers or more in diameter, leading to extinctions. It is widely believed among scientists that sixty-five million years ago an asteroid ten kilometers in diameter hit Earth and triggered the mass extinction of dinosaurs. Can we protect Earth from future asteroid catastrophes? The UN's Science and Technical Subcommittee’s Near-Earth Object Working Group and its internal panel, Action Team 14, have been working on the details of an international approach since 2001.

 As if solar flares and asteroid strikes were enought, that's not all. More rare but equally potent would be the blast of radiation from a nearby γ-ray (gamma ray) burst. A short-hard γ-ray burst, caused by the violent merger of two black holes or two neutron stars or a combination, provides the most frightening scenario. If one such blast would be directed at Earth from within 200 parsecs away (less than 1% of the distance across the Milky Way), it would zap Earth with enough high-energy photons to wipe out 30% of the atmosphere's protective ozone layer for nearly a decade. Such an event — expected once every 300 million years or so — would double the amount of ultraviolet light reaching the ground and scorch phytoplankton, which make up the base of the ocean's food web. Astronomers are unable to predict such bursts, so we have no way of knowing whether such a rare event is imminent.

What about long-soft bursts? From a distance of about 2,000 parsecs, 'long-soft' γ-ray bursts — which result from the collapse of massive stars — could also damage our planet and cause extinctions. Long-soft bursts are rarer than short-hard bursts. In addition, they are easier to spot in advance because they come from larger, brighter stars.[42]

 What quandaries arise from anticipating these potential threats from the heavens? We need to plan for our planet's future, and we need to incorporate such possibilities into our planning. With regard to solar flares, fortunately, there are ways to mitigate the damage should it occur: engineers can protect the grid with fail-safes or by turning off the power in the face of an incoming blast. With regard to a comet or asteroid strike, we will be given advanced notice. A diversion strategy could be effective, perhaps by hitting the object while it is yet far away with a nuclear bomb. We have no way to prevent gamma ray bursts from striking our Earth, but we could provide protective shields in sanctuaries for life forms we wish to restart following the event. These matters belong to our quandary. Just how will we respond? 

 A Planetary Society of Moral Deliberation?

Does astroethics require a single planetary community of moral deliberation?

  We have been suggesting that the community most appropriate for posing these quandaries and deliberating about Earth's responsibility should consist of all the peoples of Earth working together. When confronting scenarios that have a planet-wide impact, the planet as a whole should become the community of moral deliberation and provide the network to shoulder the responsibility. Planetary plans to meet such threats should be international or supranational. The principle of distributive justice may require that each nation contribute to a coordinated effort in proportion to its capability by providing either technological expertise or funding for such expertise. Planetization is a corollary to the notion of a cosmic commons. Eco-images such as "green globalization" or "spaceship Earth" connote the circumstances that lead to the concept of a single planetary society.

 In order for a single planetary community of moral deliberation to emerge, local profiteering and nationalisms will have to be superseded in the name of a higher level of human unity, including a unity between the human race and the natural realm of which we are a part. This will require a repentance--a metanoia or turning around--as the first step to a sense of planetary let alone cosmic responsibility.

 Former US Vice President Al Gore has been optimistic. "Fortunately, the awakening of the Global Mind is disrupting established patterns--creating exciting new opportunities for emergent centers of influence not controlled by elites.[elites who have set incentives] that reward unsustainable exploitation of limited resources, the destruction of ecosystems crucial to the survival of civilization, unlimited flows of pollution, and the disregard of human and social values."[43] Whether pessimistic or optimistic, a long-term global ecoethic or accompanying cosmic astroethic should be the product of a single planetary society that rises above the self-destructive greed of competing subsidiary economic forces.

 A Galactic Common Good?

Should the Common Good include the solar system and even the Galactic Commons?

  Only the invocation of the common good can successfully trump the current competition between vested interests, cost-benefit priorities, industrial ambitions, and international conflicts. A single planetary community of moral deliberation could arise only if the common good becomes its agenda.

What is the common good? Pope Paul VI helpfully defined the common good as “the sum of those conditions of social life which allow social groups and their individual members relatively thorough and ready access to their own fulfillment.”[44] More recently, the Evangelical Lutheran Church in America added: "Today, the meaning of common good or good of all must include the community of all living creatures. The meaning also should extend beyond the present to include consideration for the future of the web of life. The sphere of moral consideration is no longer limited to human beings alone."[45] Could astroethicists think of the Milky Way inclusive of all creatures living within it as the sphere of the common good?

This implies that the commons we share is larger than Planet Earth alone. It is even larger than our solar system. Why? Because Earth is nested in a larger physical context, the solar system with the sun at the center. Our sun is one star among 400 billion in the Milky Way galaxy. And the Milky Way is nested within the universe, the cosmos made up of perhaps two trillion galaxies. Astroethicist John Hart proposes a cosmic commons. "The sacred cosmic commons is a communion of commonses cosmically interrelated and integrated. It is stardust become spirit, it is atoms become life and thought, all in the presence of a transcendent-immanent, Being-Becoming, creating Spirit."[46] The entire cosmos?

Hart is inspiring. Yet, perhaps it would wisest for the time being to designate the galactic commons as the shared home for our common good. The idea of a cosmic commons might not be viable, because the light year problem basically forbids interactive communication beyond the Milky Way. The concept of responsibility seems to apply only within relationships in which communication and interaction are possible. Therefore, a commons for our galaxy seems more plausible.

Be that as it may, expanding our moral horizon beyond geocentrism to the galaxy would mark an achievement in quandary-responsibility ethical deliberation. 

Within the Milky Way Metropolis: Three Astroethical Quandaries

  Astrobiologists have already concluded that no intelligent life lives anywhere within our solar ghetto other than on Earth. The only local life to which we may owe moral responsibility will be non-human life, most likely microbial. To find intelligent life we must extend our search beyond the solar ghetto into the wider Milky Way metropolis. Beyond the Milky Way the distances between galaxies and stars is so vast that we have no conceivable prospect of inter-galactic communication. It is reasonable, however, to think of the Milky Way as a galactic commons.

 Within the Milky Way commons, the likelihood of discovering intelligent life seems to be rising with each new discovery of expolanets in the habital zone.[47] Even though we have not yet met them, our quandary might suggest dividing intelligent aliens into three preliminary categories: extraterrestrial creatures less intelligent than Homo sapiens; equal in intelligence to us; or superior in intelligence. If we add these three to our list of a dozen, we now have fifteen quandaries. (13) In the event that ETI are somewhat intelligent but less intelligent than we are, might our existing moral responsibility toward animals provide a reservoir of moral precedents? (14) In the event that ETI are equally intelligent, might our commitment to a Cosmic Golden Rule contribute to formulating our moral responsibility? (15) In the event that ETI are intellectually superior to us, might we appeal to our own history of caste and servitude if not slavery? We combat slavery on our planet only because we have come to believe in equality and dignity regardless of one's status at birth. If we Homo sapiens find ourselves objectively inferior to superior aliens, how might this previous experience of slavery with liberation apply off-Earth?[48]

 Encountering Intellectually Inferior ETI?

In the event that ETI are somewhat intelligent but less intelligent than we are, might our existing moral responsibility toward animals provide a reservoir of moral precedents?

  In the event that we terrestrials begin engagement with extraterrestrials who are our inferiors in intelligence, we would then ask: might the ethical framework for discerning our responsibility toward them be analogous to our responsibility toward Earth’s animals? If we answer affirmatively, then we would find ourselves in an inherited dialectic. On the one hand, the human race exploits all other life forms—both plants and animals—for human welfare. Animals provide food, work, clothing, and even company. Animals can be sacrificed in medical research to develop therapies that will benefit only human persons. On the other hand, we human beings have a sense of responsibility toward the welfare of animals. We respect them as intelligent beings; and we are concerned about preventing suffering to animals. In some instances, we exert considerable energy and effort to preserve their species from extinction and to insure the health of individual animals. In the case of pets, we love them to a degree that rivals loving our own family. Animals on Earth have both instrumental as well as intrinsic value. In sum, we have inherited this double relationship to our inferiors already here on Earth. Might this apply off-Earth as well?

 Regardless of level of intelligence, we further inquire: might we expect the extraterrestrials to be moral beings? All rational beings we know value reciprocity and generosity. If our new extraterrestrial neighbors exhibit a moral conscience, we terrestrials may become obligated by rules of reciprocity, fairness, and justice. Philosopher of biology Michael Ruse believes such morality is a gift of evolution given to all rational creatures. “What I argue, therefore, is that if, indeed, natural selection is at work on our extraterrestrials, we might expect to find something akin to the Categorical Imperative having evolved amongst them."[49] That is, we will be obligated at least in part to treat ETI like we want ETI to treat us, even intellectually inferior ET. Most certainly this moral logic will apply when it comes to engaging peer ETI.

 Encountering Intellectually Peer ETI

In the event that ETI are equally intelligent, might our commitment to a Cosmic Golden Rule contribute to formulating our moral responsibility?

 We have just shifted from axiological (value oriented) to deontological (command oriented) ethics by entertaining the idea that Kant's Categorical Imperative might obligate us when engaging morally alert yet intellectually inferior ETI. The formal principle from which all moral duties are derived, contended Immanuel Kant, is this: “I ought never to act except in such a way that I also will that my maxim should become a universal one.”[50] In less fancy language, Jesus made a similar point with the Golden Rule: "In everything do to others as you would have them do to you” (Matthew 7:12).

 We find a version of the Golden Rule in the teachings of Confucius in ancient China, in Thales and Aristotle in ancient Greece, and elsewhere. Richard Randolph and Christopher McKay lift up a Cosmic Golden Rule and apply it to space exploration. According to "what we call the cosmic Golden Rule," they write, "all of the Earth’s global religions contain some version of the Golden Rule. We prefer the Confucian version of the Golden Rule, which frames it as a prohibition: 'Never impose on others what you would not choose for yourself'." [51] If moral reciprocity is built in to rationality, then this would make the Cosmic Golden Rule a ripe candidate to be the foundation on which to construct an ethic for the cosmic commons and a guide to engaging peer ETI.

 In post-Enlightenment terrestrial societies, corollaries to the Golden Rule have emerged: dignity, equality, liberty, freedom, and responsibility. Might these apply to peer ETI living in an off-Earth civilization? “Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end,” wrote Kant.[52]

 Critics of the Golden Rule say it should not apply to space aliens, however. Why? Because ETI might differ from us. Therefore, we should treat space aliens not as we would treat others within our Earth commons, but, rather, the way they wish to be treated.[53] Such an argument can be dismissed as a tautology. The way we want to be treated along with the way they want to be treated is just what the Golden Rule targets.

 How would peer extraterrestrials like to be treated? Let's ask them. 

Peer ETI: Hostile

 When we speculate about peer and superior ETI, we need to refine our categories. We need to divide peer ETIs into two subcategories: hostile and peaceful. Further, we need to divide superior ETIs into three subcategories: hostile, peaceful, and salvific. Once we have discerned that ETI are our equals or our superiors in technology and perhaps in intelligence, we will need to ask whether or not they pose a threat to Earth’s security and wellbeing. How we answer this question may partially guide the moral direction we take.

 We have learned from experience on our home planet how anxiety associated with insecurity leads us Homo sapiens to strike out with violence.[54] We on Earth will find ourselves uneasy, on the verge of violence, until we can be assured that the aliens we confront mean us no harm. Whether the high-minded among us find it moral or not, the inescapable reality is that no rational discourse about ethics can take place when anxiety is high and security is low. To determine whether ETI are a threat or not will ineluctably become our first priority.

 In the event that the ETI in question are in fact hostile, then we will find ourselves working within a paradoxical framework that includes both the imputation of dignity mentioned above and our pressing need to protect our planet from alien exploitation or damage. We know from experience that whenever we are confronted with a hostile enemy from without, we find ourselves within our own society compromising human dignity. Our political leaders try to persuade our society that our targeted enemies should be reduced to “inhuman” if not demonic status; and this justifies going to war. What this indicates is that the social psychology of self-defense pits human dignity against the mustering of military support. Security trumps dignity, even if a minority of high-minded individuals predictably protest. 

 If threatened by alien hostility, we can forecast that military rhetoric will attempt an equivalent of dehumanizing and, hence, de-dignifying the ETI enemy. A nation’s leaders simply cannot embrace Jesus’ peace ethic of loving our enemies combined with turning the other cheek (Matthew 5-7). So, as difficult as it may sound, we will need an ethic that affirms the dignity of ETI while rallying our Earth allies in planetary defense. We might need to adapt for peer ETI the Race and Randolph principle, “cause no harm to Earth, its life, or its diverse ecosystems,” within a tense relationship to the wider ethical principle of imputing dignity to our extraterrestrial peers. 

 Peer ETI: Peaceful 

 In the event that peer ETI prove to be neutrally peaceful or even benevolent, then the principles giving expression to Enlightenment values should prevail without challenge: equality, liberty, freedom, dignity, and mutuality.  

Encountering Intellectually Superior ETI? 

In the event that ETI are intellectually superior to us, might we appeal to our own history of caste and servitude if not slavery? 

 As we adumbrate our quandaries, we are engaged in a series of thought experiments. When entertaining these thought experiments, it might be challenging to imagine up. We already know how to imagine down. When comparing humans with animals, for example, we can imagine down by distinguishing things we humans can do that are beyond the capability of the animal with whom we already share a commons. When it comes to imagining ETI who might be superior to us in intelligence, we will have to imagine just how superior intelligence could manifest itself. This will be challenging, especially if extraterrestrial brain power lies beyond the very human intelligence that is doing the imagining. This puts initial constraints or limits on how we can begin to approach the topic of ethics when engaging ETI more advanced than Earth’s Homo sapiens. Nevertheless, it is incumbent on the astroethicist to try.

 At one level, it may be easy to forecast that any extraterrestrial intelligent civilization SETI or METI contacts would be our superiors. Why? Because of the ETI myth. According to the myth, biological evolution is progressive, leading from simple to complex and from stupid to intelligent. Similarly, culture evolves so that our minimally intelligent ancestors have been succeeded by the most intelligent creatures yet in Earth's evolutionary history, namely, the scientists. Scientists declare themselves to be the apex of evolution, the crown of creation. So scientists imagine that when we make contact with a more advanced civilization in space--a civilization which has evolved longer and progressed further--we will make contact with extraterrestrial super-scientists. The ETI myth, like myths told by ancient kings, functions to legitimate the myth teller. In this case, the myth teller is the scientist next door.

 All this is to say that the idea that the ETI we encounter will be more advanced and more intelligent than we is already alive and well in the scientific community. Therefore, astroethical speculation is warranted. 

 Superior ETI: Post-Biological Intelligence 

 Just what might advanced ETI with superior intelligence have already achieved? Perhaps ETI already live as disembodied intelligence.

 This is the transhumanist scenario. On Earth today, transhumanists are scientists who idolize intelligence and plan to advance our race to the next level, to superintelligence. From superintelligence, our descendents will advance to disembodied intelligence, jettisoning our biological bodies so rife with disease, aging, and death. Disembodied intelligence will be everlasting, eternal.

 The threshold to be crossed is dubbed the Singularity, when the human mind will be uploaded into the computer cloud. Once in the computer, we will not age like we would in our bodies. If a computer breaks down, someone can simply copy and upload our mental life into another computer. This could go on forever, in principle.

 Once liberated from the limits of aging or even from our physical bodies themselves, the expansion of human intelligence would be limited only by the size of our universe. We will travel mentally throughout our solar ghetto, throughout the Milky Way Metropolis, and beyond to the outer reaches of the universe. What Hans Moravec foresees is a cosmic imbuing of matter with our consciousness. “Liberated from biological slavery, an immortalized species, Homo cyberniticus, will set out for the stars. Conscious life will gradually spread throughout the galaxy.until finally, in the unimaginably distant future, the whole universe has come alive, awakened to its own nature—a cosmic mind become conscious of itself as a living entity—omniscient, omnipotent, omnipresent.”[55]

 The entire universe will be converted into an “extended thinking entity,” writes Moravec.[56]   If the transhumanists actualize the potential residing in their futuristic vision, the more intelligent creatures who replace us will enjoy a level of salvation that we in our generation will never experience.

 With this terrestrial scenario in mind, could we imagine that something like this has already happened to one or more races of alien intelligences? Yes. If we establish contact, might it be with the post-alien machines enjoying cybernetic immortality and spreading throughout the stars?

 Cambridge physicist and cosmologist Martin Rees entertains the possibility of artificial intelligence if not posthuman intelligence residing on an exoplanet. "The most likely and durable form of life may be machines whose creators had long ago been usurped or become extinct."[57] In outer space we earthlings may meet our own posthuman future.

 Would we have any moral obligation to non-biological or posthuman intelligence? If we use contemporary experience on Earth with computers as a model, the answer is negative. Destroying or recycling computer hardware or software elicits within us no moral sensitivity. We know tacitly that we are not snuffing out the consciousness of a sentient being when we press the "delete" button. If the machines we encounter in space exhibit artificial intelligence, then unplugging them could be done without moral consequence.

 However, if the machines we encounter are actually the living tombs of immortalized aliens who exchanged their biological bodies for plastic and silicon hardware, then we might give moral pause. We may find we should treat our conscious alien friends with the kind of dignity entertained in our previous discussion of peer ETI. We might offer to clean the keyboard and secure the plug in the wall socket, perhaps even to play a hand of Bridge or two and keep them company.      

 Superior ETI: Still Biological Yet Intellectual 

 If we meet embodied ETI superior to ourselves, will they be hostile? Neutrally peaceful? or salvific? Given the assumptions made by astrobiologists that extraterrestrial evolution will follow a path toward increased intelligence as it has on Earth, the prospect of ETI fitting the hostile category is to be expected. Charles Darwin’s key evolutionary principle is “natural selection,” which he identifies with “the struggle for existence’ and with  Herbert Spencer’s phrase, “survival of the fittest.”[58] In the struggle for existence, living creatures undergo cruelty, suffering, and waste.[59] And the species to which virtually every individual creature belongs will eventually go extinct to make way for a more fit species. The strong devour the weak. The big eat the small. The fit survive in a world that is, as Tennyson put it, blood “red in tooth and claw.”

 Even slavery is not unknown in the pre-human struggle for existence. One species of red ant (formica sanguinea) enslaves a species of black ants (formica fusca) to gather food and make nests, observes Darwin. “The slaves are black and not above half the size of their red masters.”[60] If we would substitute intelligence for size and ascribe it to the ETI we meet, perhaps they might decide to enslave Homo sapiens for their gain in the struggle for existence. This prospect would be most consistent with the theory of evolution as we project it onto planets among the stars.

 Given astrobiological assumptions regarding a repeat of evolution on extraterrestrial planets, hostility is what we should expect on the part of ETI. Yet, surprisingly, some SETI speculators anticipate meeting intellectually superior ETI who will benevolently help us on Earth. For this reason, we need to add the subcategory of salvific. Now, how do we get from the struggle for existence to extraterrestrial saviors? How does evolution transcend itself? Does any empirical evidence exist for such a belief?

 The astroethicist here needs to discern the logic inherent within SETI thinking. As we have noted, some in the astrobiology community project an image of a more highly evolved extraterrestrial creature who would like to rescue us earthlings from the ignorant habits we have developed due to our inferior level of intelligence. Because we on Earth have not yet achieved the level of rationality necessary to see that international war and planetary degradation are inescapably self-destructive, we could learn from ETI more advanced than we. "All technological civilizations that already have passed through their technological adolescence and have avoided their self-destruction.must have developed ethical rules to extend their societal life expectancy," says Guillermo Lemarchand, speaking for the space community.[61] Because they are beyond war, spacelings can help earthlings get beyond war.

 Such thinking is obviously myth, not science. No empirical evidence justifies such speculation; and this introduces incoherence into the theory that extraterrestrials have evolved in the same we that we have evolved. Yet, such dreaming of redemption descending from the skies is tantalizing to the terrestrial imagination. The essence of the ETI myth is that science saves. Science can save Earth from its inadequacies, its evolutionary backwardness, its propensity for self-destruction. If terrestrial science is insufficient, then extraterrestrial science just might be.

 SETI's founder and champion, Frank Drake, looks forward to salvation for Earth descending from the science in the sky. “Everything we know says there are other civilizations out there to be found. The discovery of such civilizations would enrich our civilization with valuable information about science, technology, and sociology. This information could directly improve our abilities to conserve and to deal with sociological problems—poverty for example. Cheap energy is another potential benefit of discovery, as are advancements in medicine.”[62] Note the optimism. Drake does not expect what Darwin would expect, namely, an extraterrestrial race engaged in the struggle for existence which might like to exploit us on Earth. Rather, Drake’s extrapolation of evolution to ETI imagines an intelligent and benevolent race ready to offer us aid and assistance. His vision includes optimism regarding the solution to Earth’s “sociological” problems such as poverty and energy. Space visitors might even give us a leap forward in medicine.

 What Drake believes is that science is salvific, and extraterrestrial science would be even more salvific than terrestrial science. In sum, should an extraterrestrial civilization more evolutionarily advanced than we engage planet Earth, we could benefit from the ability of ETI to save us from our own primitive inadequacies and even our own propensity for self-destruction. It is this thought structure within astrobiology that warrants the designation for more highly evolved and more intelligent ETI as “celestial saviors.” 

Hostile Superior ETI: Ethics of Enslavement 

 If superior ETI follow the standard Darwinian model and confront us with hostile and exploitative enslavement, then perhaps we will frame our ethics accordingly. The New Testament provides instructions for slaves. “Slaves, accept the authority of your masters with all deference, not only those who are kind and gentle but also those who are harsh” (1 Peter 2:18). This may seem as unrecognizable as it is repugnant. The treatment of the superior master by an inferior slave has fallen into disuse in our post-Enlightenment period. This is because of the erasure of the line between superior and inferior human beings within modern Enlightenment culture. We are all equal—that is, we are all ethically equal. Each of us has dignity by virtue of our belonging to a single moral set: the human race; and slavery violates the principle of dignity which we ascribe to every individual member of this moral set. Should a master-slave relationship rear its ugly head somewhere on our planet, we children of the Enlightenment would encourage the slaves to rebel and strive for their own liberation. Such a moral commitment to liberation would be justified by the assumption that both masters and slaves are equal.

 Yet, if we bite the bullet and recognize that by our own criterion of measurement--intelligence--ETI are superior to us, then we must admit the logic that follows. As we treat animals, so also ETI could treat us without moral opprobrium. Like animals, we Homo sapiens would be compelled to do the bidding of our slave masters. Our moral responsibility would be to grant superior ETI the respect they are due. 

 Salvific Superior Aliens: Ethics of Gratitude 

 Let us now abandon the trajectory of the enslaving ETI and turn to the second subcategory: peaceful. In the event that ETI approach the civilizations on Earth in a peaceful manner, we would want to respond with an appropriate ethic of peace. Maintaining peace with justice would become our middle axiom, linking our vision of a cosmic commons to every day activity. We might even find ourselves organizing to quiet down and restrict earthly voices among us that would disturb the peace. We would want to police ourselves in the name of peace. Peace would benefit life on Earth. In addition, moral policies we set would likely treat our alien superiors with dignity, respect, and courtesy due to their position of superiority and potential power.

 What if Frank Drakes dream comes true? In the event that ETI turn out to be not only more intelligent but also altruistic toward us, then an ethic of gratitude might be included in our responsibility. We would receive and make use of the gifts that increased intelligence would allegedly provide us: such as the means for maintaining a healthy planetary ecology, improvement in our medical care, and more justice in our social practices. Then, we would build upon what we have already said about maintaining terrestrial peace and treating our superiors with dignity; we would add a measure of grateful respect. The middle axiom in this case would be simple: gratitude.

 In summary, we should treat superior ETI with dignity, respecting and even caring for their welfare. If they are hostile and enslave us, we should invoke an appropriate slave morality that maintains their dignity. If ETI are peaceful toward us and open up avenues of conversation and commerce, then the principles of justice and the striving to maintain peace should obtain. If out of their superior wisdom and altruistic motives ETIL seek to better our life here on Earth, we should accept the gifts they bring and respond with an attitude of gratitude.  


"The job of ethics is to evaluate issues of right and wrong, or good and bad, directing our focus to normative questions of value," say space philosophers Carol Cleland and Elspeth Wilson.[63] In this treatment of astroethics, we have not provided a thorough foundation for ethics let alone established normative standards. We have, however, listed and evaluated quandaries raised by the prospect of space exploration.

Astroethics has been newly elected to the congress of moral policy makers. Despite being a freshman, astroethics is ready to introduce measures to be considered. Within our solar ghetto, we must provide ethical deliberation prompted by the prospect that we will be traveling in outer space and that we may discover primal or microbial life, what astrobiologists have dubbed unintelligent life. These prospects elicit a moral quandary regarding matters such as: planetary protection (including protection of Earth and protection of off-Earth ecospheres); the intrinsic value of extraterrestrial life and of off-Earth ecosystems; what to do about space junk; satellite spying; weaponization of space; the competition between scientific research and economic interests, including space tourism; terraforming Mars; Mars colonization; mitigating the damage done by solar flares, asteroid collisions, and gamma bursts; and such.

 Because SETI and METI scientists along with astronomers the world over have been testing exoplanets for signs of intelligent life, astroethicists must begin speculating on what contact and engagement might lead to. If we engage an extraterrestrial population of beings less intelligent than us, might we formulate our moral responsabilies draw in light of our relationship with animals on Earth? If we engage with an extraterrestrial population of beings equal to us in intelligence, might we re-appropriate values drawn from the Western Enlightenment: dignity, liberty, freedom, and mutuality? If we engage with a hostile civilization of beings superior to us in intelligence, might we become their slaves? If we engage with an altruistic civilization of beings superior to us in intelligence and if this results in the salvation of life on Earth, might we feel it's only right to express gratitude?

 These quandaries prompt in us a sense of responsibility. The very knowledge that such challenges may be approaching us in the future is sufficient to prompt in us the question: what should we do? The matter becomes more complex when we ask: just who makes up the community of moral deliberation on Earth? It appears obvious that challenges to the future of all life on Earth--actually, all life in the galactic commons--lead to a warrant for a single planetary community of moral deliberation. All peoples of Earth in cooperation need to deliberate over what is best for our planet as a whole, and our cosmic commons as a whole. Can the peoples of Earth think of themselves as a single planetary society shouldering responsibility for all biota and even abiotic factors in our solar ghetto? In our galaxy?


[1] Department of Space: Indian Space Research Organization, https://www.isro.gov.in/about-isro/vision-and-mission-statements (accessed 10/27/1017).

This entry draws heavily from chapters 22 and 23 in Astrotheology: Science and Theology Meet Extraterrestrial Life, eds., Ted Peters, Martinez Hewlett, Joshua M. Moritz, and Robert John Russell. Eugene OR: Cascade Books, 2018. See also: Peters, Ted, "Got Ethics for the Galaxy? Quandary-Responsibility Ethics for Space Exploration," Science-Religion Dialogue and Its Contemporary Significance: Interdisciplinary Essays in Honor of Prof. Dr. Kuruvilla Pandikattu, ed., Binoy Pichalakkattu. Bengaluru, India: ATC Publishers, 2018; 9-36. See also: Peters, Ted, "Stretching Twelve AstroEthical Issues Within Our Solar Ghetto to Address Warfare in the Milky Way Metropolis." METI (2017). http://meti.org/blog/stretching-twelve-astroethical-issues-within-our-solar-ghetto-address-warfare-milky-way; Spanish Version: https://www.facebook.com/METIintl/posts/789998257845584:0 .

[3] A similar term, astrobioethics, has already gained some usage. "Astrobioethics is the subsection within astrobiology that is accountable for studying the moral implications of, for example, bringing humans to Mars, the Planetary Protection Policy, the social responsibility of the astrobiologist to society, etc." Chon-Torres, Octavio, "Astrobioethics," International Journal of Astrobiology 16:2 (April 2017) 1-6, at 1; doi:10.1017/S1473550417000064

[4] http://portal.unesco.org/shs/en/ev.php-URL_ID=1837&URL_DO=DO_TOPIC&URL_SECTION=201.html.

[5] Schwartz, James S.J., "On the Methodology of Space Ethics," The Ethics of Space Exploration, eds., James S.J. Schwartz and Tony Milligan. Heidelberg: Springer, 2016; 93-107, at 106.

[6] Tripathi, A.N., "Scientific Developments and Ethical Values," Omega: Indian Journal of Science and Religion 1:1 (December 2002) 96-105, at 101.

[7] It may be the case that all life is intelligent, even simple organisms. If this is the case, then we might dub intra-solar life relatively more simple and exoplanet civilizations relatively more complex. Peters, Ted, "Where There's Life There's Intelligence," in What is Life? On Earth and Beyond, ed., Andreas Losch.                Cambridge University Press, 2017; 236-259.

[8] “Observations of Saturn’s moon Titan over several years show that its rotational period is changing and is different from its orbital period.” What this most likely means is that Titan’s shifting crust sits atop an interior ocean, perhaps a water-ammonia ocean that is “potentially habitable. Internal oceans have been detected magnetically on Europa and Callisto and are also presumed to exist on Ganymede” Ralph D. Lorenz, Bryan W. Stiles, Randolph L. Kirk, Michael D. Allison, Paolo Persi del Marmo, Luciano Iess, Jonathan I. Lunine, Steven J. Ostro, and Scott Hensley, “Titan’s Rotation Reveals an Internal Ocean and Changing Zonal Winds.” Science 319:5870 (21 March 2008) 1649-1651: 1649-1650.

[9] "From an ethical perspective, this means that the primary principle for engaging in Active SETI should be the avoidance of harm — and this applies not only to human civilization, but also to the civilization at the other end of a transmission."[9] Traphagen, John W., "Do No Harm? Cultural Imperialism and the Ethics of Active SETI," Journal of the British Interplanetary Society 70 (2017) 219-224, at 224.

[10] Race, Margaret S., and Richard O. Randolph,  “Societal and Ethical Concerns,” in Planets and Life: The Emerging Science of Astrobiology, ed. Woodruff T. Sullivan, III, and John A. Baross. Cambridge UK: Cambridge University Press, 2007; 483-497, at 495.

[11] This adumbration differs moderately from that offered by James S.J. Schwartz, "Introduction: The Scope and Content of Space Ethics," Ethics of Space Exploration, 1-14; at 2.

[12] This ethical quandary is one of the most important, because it requires a moral commitment that extends beyond anthropocentric interest. “Respect the extraterrestrial ecosystem and do not substantively or irreparably alter it (or its evolutionary trajectory).” Margaret S. Race and Richard O. Randolph,  “The Need for Operating Guidelines and a Decision Making Framework Applicable to the Discovery of Non-Intelligent Extraterrestrial Life,” Advances in Space Research, 30:6 (2002)1583-91. http://www.seti.org/pdfs/m_race_guidelines.pdf .

[13] Conley, Catherine A., and John D. Rummel, "Planetary protection for human exploration of Mars," Acta Astronautica 66:5-6 (March-April 2010) 792-797;

http://www.sciencedirect.com/science/article/pii/S0094576509004317. See: "Life Guard: an Interview with Catharine Conley," Scientific American 311:4 (October 2014) 30.

[14] Collins, Nathan, "Stop Pampering the Red Planet," Scientific American 309:3 (September 2013) 24.

[15] Cited by Collins, ibid.

[16] This ethical quandary is one of the most important, because it requires a moral commitment that extends beyond anthropocentric interest. “Respect the extraterrestrial ecosystem and do not substantively or irreparably alter it (or its evolutionary trajectory).” Race and Randolph,  “The Need for Operating Guidelines."

[17] Lupisella, Mark, "Cosmological Theories of Value: Relationalism and Connectedness as Foundations for Cosmic Creativity," Ethics of Space Exploration, 75-92, at 80.

[18] Ibid., 89.

[19] Cockell, Charles S., "The Ethical Status of Microbial Life on Earth and Elsewhere: In Defense of Intrinsic Value," Ethics of Space Exploration, 167-180, at 169.

[20] Randolph, Richard O., "God's preferential option for life: a Christian perspective," in Exploring the Origin, Extent, and Future of Life: Philosophical, Ethical, and Theological Perspectives, ed. Constance M. Bertka. Cambridge UK: Cambridge University Press, 2009; 287.

[21] Ibid.

[22] Peters, Ted, "Does Extraterrestrial Life Have Intrinsic Value? An Exploration in Responsibility Ethics," International  Journal of Astrobiology 17:2 (2018) 1-7; https://doi.org/10.1017/ S147355041700057X; https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/does-extraterrestrial-life-have-intrinsic-value-an-exploration-in-responsibility-ethics/5DCA161726CE8F4FC9E58EE8E6D04B81 .

 [23] Deane-Drummond, Celia E., "The alpha and the omega: reflections on the origin and future of life from the perspective of Christian theology and ethics," in Exploring, 104.

[24] Conley and Rummel, "Planetary protection for human exploration of Mars."

[25] The so-called Wingspread Definition of the Precautionary Principle was formulated at the 1992 United Nations Conference on Environment and Development. See: Wingspread Conference, Racine, Wisconsin, 1998. See: David Appell, “the New Uncertainty Principle,” Scientific American (Jan. 18, 2001) 18.

[26] “COSPAR Workshop on Ethical Considerations for Protection in Space Exploration, Princeton University, Princeton, NJ, 8-10, 2010.

 [27] NASA, "Space Debris and Human Spacecraft," https://www.nasa.gov/mission_pages/station/news/orbital_debris.html.

[28] Marks, Paul, “Clearing the heavens, one piece at a time,” New Scientist 209:2799:22 (12 February 2011) 22.

[29] ESA Space Debris Office,

http://www.esa.int/Our_Activities/Operations/Space_Debris/ESA_Space_Debris_Office (accessed 1/21/2013).

[30] "Researchers Eye Tethers for Space Debris," Science 343:6175 (7 March 2014) 1062.

[31] Arnould, Jacques, Icarus' Second Chance: The Basis and Perspectives of Space Ethics. Heidelberg: Springer, 2011; 105.

[32] Ibid., 75.

[33] Billings, Linda, "A U.S. Space Force? A Very Bad Idea," Theology and Science 16:4 (November 2018) 385-387, at 387; https://www.tandfonline.com/doi/full/10.1080/14746700.2018.1522732.

[34] See: Stern, S. Alan, "The Low-Cost Ticket to Space," Scientific American 308:4 (April 2013) 69-73.

[35] McKay, Christopher P., "Planetary ecosynthesis on Mars: restoration ecology and environmental ethics," in Exploring, 259.

[36] Francisca Cho, “An Asian Religious Perspective on Exploring the Origin, Extent and Future of Life,” in Workshop Report: Philosophical, Ethical, and Theological Implications of Astrobiology, edited by Connie Bertka, Nancy Roth, and Matthew Shindell. Washington DC: AAAS, 2007; 208-218: 212.

[37] Zubrin, Robert, "Why Earthlings Should Colonize Mars?" Theology and Science 17:3 (August 2019) https://www.tandfonline.com/doi/full/10.1080/14746700.2019.1632519 or https://www.researchgate.net/publication/333913038_Why_We_Earthlings_Should_Colonize_Mars.

[38] Billings, Linda, "Should Humans Colonize Other Planets? No!" Theology and Science 15:3 (August 2017) 321-332, at 321; https://www.tandfonline.com/doi/full/10.1080/14746700.2017.1335065 or file:///C:/Users/Ted/Downloads/Billings.colonizeMars_No.TS.4.15.19.pdf/

[39] Mars Direct, http://www.marssociety.org/home/about/mars-direct, accessed 1/25/2013.

[40] Crysdale, Cynthia S.W., "God, evolution, and astrobiology," in Exploring, 240.

[41] Morin, Monte, "Russian Meteor was actually a Tiny Asteroid, NASA says," Los Angeles Times (February 15, 2013) http://www.latimes.com/news/science/sciencenow/la-sci-sn-russian-tiny-asteroid-20130215,0,5424522.story?track=rss.

[42] Nature Editorial, "Realities of Risk" Nature (8 January 2013) https://mail.google.com/mail/?tab=wm#inbox/13c20ba8ce39aa0d (accessed 1/18/2013).

[43] Gore, Al, The Future: Six Drivers of Global Change. New York: Random House, 2013; 364.

[44] “Pastoral Constitution on the Church in the Modern World: Gaudium Et Spes, promulgated by His Holiness, Pope Paul VI on December 7, 1965,” No. 26, The Holy See, accessed May 7, 2016, http://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19651207_gaudium-et-spes_en.html

[45] Evangelical Lutheran Church in America, "Genetics, Faith, and Responsibility," (2011) http://download.elca.org/ELCA%20Resource%20Repository/GeneticsSS.pdf?_ga=1.54478571.232821864.1462997417.

[46] Hart, John, Cosmic Commons: Spirit, Science, and Space. Eugene OR: Cascade Books, 2013, 15.

[47] See: NASA on exoplanet discoveries. https://www.nasa.gov/content/exoplanet-discoveries  (accessed 2/26/2017).

[48] See: Peters, Ted, "Astroethics: Engaging Extraterrestrial Intelligent Life-Forms," Encountering Life in the Universe, eds., Chris Impey, Anna Spitz, & William Stoeger (Tucson: Univ. Arizona Press, 2013) 200-221. See also: Peters, Ted, "Intelligent Aliens and Astroethics," Space Exploration and ET: Who Goes There? ed., Jacques Arnould (Adelaide, Australia: ATF Press, 2014) 1-20.

[49] Ruse, Michael, “Is Rape Wrong on Andromeda? An Introduction to Extraterrestrial Evolution, Science, and Morality,” in Extraterrestrials: Science and Alien Intelligence, ed. Edward Regis, Jr. (Cambridge: Cambridge University Press, 1985) 43-78: 65.

[50] Kant, Immanuel, (1948). Groundwork of the Metaphysic of Morals, tr. H. J. Paton (New York: Harper, 1948) 70; See: Jan Narveson, “Martians and Morals: How to Treat an Alien,” in Extraterrestrials, 245-266: 248.

[51] Randolph and McKay, "Protecting," citing Confucius, Analects XV.24, translated by David Hinton in The Analects [of Confucius], Washington, D.C.: Counterpoint Press 1998).

[52] Kant, Groundwork, 96.

[53] Time, “Religion: Space Ethics," (October 1, 1956),  http://www.time.com/time/magazine/article/0,9171,862394,00.html.

[54] On anxiety and security, see: Peters, Ted, Sin: Radical Evil in Soul and Society. Grand Rapids: Eerdmans, 1994.

[55] Moravec, Hans, Mind Children: The Future of Robot and Human Intelligence. Cambridge MA: Harvard University Press, 1988; 44.

[56] Ibid., 116.

[57] Rees, Martin, Our Final Hour. New York: Basic Books, 2003; 167.

[58] Darwin, Charles, The Origin of Species By Means of Natural Selection of the Preservation of Favoured Races in the Struggle for Life. New York: Signet, 6th ed., 2003; 89.

[59] Ibid., 445.

[60] Ibid., 245.

[61] Lemarchand, Guillermo A., "Speculations on First Contact," When SETI Succeeds: The Impact of High-Information Contact, ed. Allen Tough. Bellevue WA: The Foundation For the Future, 2000; 154.

[62] Richards, Diane, “Interview with Dr. Frank Drake,” SETI Institute News (2003) 12:1; First Quarter, 5.

 [63] Cleland, Carol E. and Elspeth M. Wilson, "Lessons from Earth: Toward and Ethics of Astrobiology," in Encountering Life in the Universe,17-55, at 29.



Ethics Astroethics Astrobiology ETI SETI Planetary Protection METI Mars NASA Precautionary Principle